1. Field of the Invention
The present invention relates to a hybrid semiconductor-ferromagnet device with a junction structure of positive and negative magnetic-field regions.
2. Description of the Background Art
Hybrid semiconductor-ferromagnet devices have been spotlighted as devices applicable in the fields, such as magnetic field-sensors, non-volatile memory devices, spintronics, etc., which are recently attracting attentions. Especially, sensors based on the magnetoresistance of hybrid semiconductor-ferromagnet devices are next generation technologies which may be essential for the technologies of high-density data storage and position/speed monitoring devices. In such devices, the motion of the electrons in the semiconductor can be controlled by using local nonhomogeneous magnetic fields.
Another magnetic-field sensors that have been recently highlighted include GMR and TMR devices. However, these devices have drawbacks in some applications. Especially, in the fields of biomolecule sensors using magnetic beads that have been recently highlighted, the device suggested in the present invention shows superior performance to the GMR and TMR devices.
Recently, Solin et al. reported an extraordinary magnetoresistance (EMR) device. The EMR device shows a high MR, but it requires a very low contact resistance between the semiconductor and the metal and is not easy to fabricate.
The hybrid ferromagnet-semiconductor devices reported up to now have been devices in which a positive local magnetic field region and a negative local magnetic field region are separated from each other, even if local magnetic fields are one-directional, or local magnetic fields of opposite directions are formed on a single device, and in which voltage probes for sensing the amplitude of signals are located regardless of the direction of local magnetic fields.